29809-25-4Relevant articles and documents
Light-Activated COS/H2S Donation from Photocaged Thiocarbamates
Zhao, Yu,Bolton, Sarah G.,Pluth, Michael D.
, p. 2278 - 2281 (2017)
Hydrogen sulfide (H2S) is an important biomolecule, and responsive chemical tools for its delivery are needed. Here, we utilize the photocleavable o-nitrobenzyl group to unmask caged thiocarbamates and to access photoactivated H2S releasing molecules. These donors function by the initial release of carbonyl sulfide (COS), which is quickly hydrolyzed to H2S by carbonic anhydrase (CA). Our investigations demonstrate that o-nitrobenzyl-caged thiocarbamates can serve as a donor platform for the bio-orthogonal stimulated release of COS/H2S.
Photoresponsive micelles enabling codelivery of nitric oxide and formaldehyde for combinatorial antibacterial applications
Duan, Yutian,He, Kewu,Zhang, Guoying,Hu, Jinming
, p. 2160 - 2170 (2021)
It is of particular interest to develop new antibacterial agents with low risk of drug resistance development and low toxicity toward mammalian cells to combat pathogen infections. Although gaseous signaling molecules (GSMs) such as nitric oxide (NO) and formaldehyde (FA) have broad-spectrum antibacterial performance and the low propensity of drug resistance development, many previous studies heavily focused on nanocarriers capable of delivering only one GSM. Herein, we developed a micellar nanoparticle platform that can simultaneously deliver NO and FA under visible light irradiation. An amphiphilic diblock copolymer of poly(ethylene oxide)-b-poly(4-((2-nitro-5-(((2-nitrobenzyl)oxy)methoxy)benzyl)-(nitroso)amino)benzyl methacrylate) (PEO-b-PNNBM) was successfully synthesized through atom transfer radical polymerization (ATRP). The resulting diblock copolymer self-assembled into micellar nanoparticles without premature NO and FA leakage, whereas they underwent phototriggered disassembly with the corelease of NO and FA. We showed that the NO- and FA-releasing micellar nanoparticles exhibited a combinatorial antibacterial performance, efficiently killing both Gram-negative (e.g., Escherichia coli) and Gram-positive (e.g., Staphylococcus aureus) bacteria with low toxicity to mammalian cells and low hemolytic property. This work provides new insights into the development of GSM-based antibacterial agents.
The early processes in the photochemistry of ortho-nitrobenzyl acetate
Schmierer,Bley,Schaper,Gilch
, p. 363 - 368 (2011)
The early processes in the de-caging of acetic acid from o-nitrobenzyl acetate (oNBAc) were studied by femtosecond techniques. Solutions of oNBAc in acetonitrile were excited by 260 nm laser pulses and the resulting spectroscopic changes probed by transient absorption and stimulated Raman spectroscopy. Absorption and Raman data give evidence of the formation of an aci-nitro species resulting from an intramolecular hydrogen transfer. The species is formed on the 1 ps and 1 ns time scale in equal amounts. The two processes are attributed to hydrogen transfers via a singlet and a triplet channel. The overall quantum yield of the aci-nitro formation is 0.1 matching the de-caging yield.
Davis-Beirut Reaction: A Photochemical Br?nsted Acid Catalyzed Route to N-Aryl 2 H-Indazoles
Kraemer, Niklas,Li, Clarabella J.,Zhu, Jie S.,Larach, Julio M.,Tsui, Ka Yi,Tantillo, Dean J.,Haddadin, Makhluf J.,Kurth, Mark J.
supporting information, p. 6058 - 6062 (2019/08/20)
The Davis-Beirut reaction provides access to 2H-indazoles from aromatic nitro compounds. However, N-aryl targets have been traditionally challenging to access due to competitive alternate reaction pathways. Previously, the key nitroso imine intermediate w
Synthesis and photochemical studies of 2-nitrobenzyl-caged N-hydroxysulfonamides
Zhou, Yang,Bharadwaj, Vinay,Rahman, Mohammad S.,Sampson, Paul,Brasch, Nicola E.,Seed, Alexander J.
, (2019/09/09)
Recently, N-hydroxysulfonamides (RSO2NHOH) caged by photolabile protecting groups have attracted significant interest as potential photoactive nitroxyl (HNO) donors. The selectivity of the desired HNO generation pathway from photocaged N-hydroxysulfonamides versus a competing pathway involving O-N bond cleavage is dependent on the specific photodeprotection mechanism of the phototrigger. We present a new class of photocaged N-hydroxysulfonamides incorporating the well-established o-nitrobenzyl photoprotecting group, including a derivative incorporating an additional carbonate linker. Photodecomposition of o-NO2Bn-ON(H)SO2CF3 and the corresponding 2-nitro-4,5-dimethoxybenzyl analog generated the desired HNO and CF3SO2- as a minor pathway, with competing photoinduced O-N bond cleavage to release CF3SO2NH2 as the major photodecomposition pathway. Photolysis of the corresponding -SO2CH3 analogs resulted in O-N bond cleavage only. The presence of the o-nitro substituent was shown to be essential for photoactivity. Photorelease of the parent HNO donor CH3SO2NHOH was observed as the major product upon irradiation of o-NO2Bn-OC(O)ON(H)SO2CH3, with the desired HNO release and O-N bond cleavage occurring as minor pathways. Photoproduct quantum yields for each species have been determined by actinometry. The effect of solvent, pH and air on the mechanism of photodecomposition was studied for o-NO2Bn-ON(H)SO2CH3. The ratio of the solvents in the solvent mixture (CH3CN and phosphate buffer, pH 7.0), the pH of the aqueous component of the buffer, and the presence of oxygen did not affect the amount of each photoproduct and the observed rate constant for O-N bond cleavage. Possible mechanisms for the various pathways are proposed.
